Kristína Gerulová

Preliminary Study of Utilizing Ozone in Treatment of Operationally Exhausted Metalworking Fluids

The article deals with preliminary study of possible utilization of ozone oxidative capacity for eliminating the organic content of operationally exhausted MWFs. This research was focused on the treatment of 17 samples clean MWFs diluted concentrates (samples mostly from Castrol, Shell Macron GmbH, Fuchs Oil corp., Agip GmbH, Blaser Swisslube AG, Cimcool Industrial Products BV, Houghton, Exxon Mobile and Quaker) by ozone. The study is focused to the effect of high concentrations of ozone during 4 hours on the kinetics of total organic content using parameters such as COD and TOC. The concentration of the tested MWFs was set at 1% (v/v). Selected MWFs consisted of all types of water miscible – emulsions, semi-synthetic and synthetic fluids.

Characterisation Of Polysacharides And Lipids From Selected Green Algae Species By FTIR-ATR Spectroscopy

Abstract Fourier transform infrared (FTIR) spectroscopy was used in this study to identify and determine spectral features of Chromochloris zofingiensis (Dönz) Fucíková et L.A. Lewis (SAG 211-14, Gottingen, Germany), Acutodesmus obliguus (Turpin) Hegewald (SAG 276-1, Gottingen, Germany) and Chlorella sorokiniana (K. Brandt) Pröschold et Darienko (SAG 211-40c, Gottingen, Germany). Polysaccharides and lipids from these three algae species were determined using Fourier Transformed Infrared Spectroscopy (FTIR) with ATR accessory with diamante crystal in spectral range from 400 – 4000 cm−1 and resolution 4.

Preliminary Ecotoxicity and Biodegradability Assessment of Metalworking Fluids

Preliminary Ecotoxicity and Biodegradability Assessment of Metalworking Fluids The main aim of this study was to evaluate the potential of activated sludge from sewage treatment plant to degrade selected MWFs (ecotoxicity to bacterial consortium) and to evaluate the ecotoxicity by Lemna minor-higher plant. After evaluating the ecotoxicity, biodegradations rate with activated sludge was assessed on the basis of COD measurement. Preliminary study of measuring the ecotoxicity according to OECD 221 by Lemna minor shows effective concentration of Emulzin H at the rate of 81.6 mg l-1, for Ecocool 82.9 mg l-1, for BC 25 about 99.3 mg l-1, and for Dasnobor about 97.3 mg l-1. Preliminary study of measuring the ecotoxicity by bacterial consortium according to OECD 209 (STN EN ISO 8192) shows effective concentration of Blasocut BC 25 at the rate 227.4 mg l-1. According to OECD 302B, the biodegradations level of Emulzin H, Ecocool and BC 25 achieved 80% in 10 days. It can be stated that these MWFs have potential to ultimate degradation, but the statement has to be confirmed by a biodegradability test with other parameters than COD, which exhibits some disadvantages in testing O/W emulsions.

Cultivation Of Microalgae (Chlorella vulgaris) For Biodiesel Production

Abstract Production of biofuel from renewable sources is considered to be one of the most sustainable alternatives to petroleum sourced fuels. Biofuels are also viable means of environmental and economic sustainability. Biofuels are divided into four generations, depending on the type of biomass used for biofuels production. At present, microalgae are presented as an ideal third generation biofuel feedstock because of their rapid growth rate. They also do not compete with food or feed crops, and can be produced on non-arable land. Cultivation conditions (temperature, pH, light, nutrient quantity and quality, salinity, aerating) are the major factors that influence photosynthesis activity and behaviour of the microalgae growth rate. In this paper, we present an overview about the effect of cultivation conditions on microalgae growth.

Human Health Concenrs of the Metalworking Fluid Components

Abstract Exploration of 209 available Material safety data sheets of 85 straight oils, 46 emulsions, 51 semi-synthetics and 27 synthetics was carried out to provide a report on the most widely used components defined as dangerous substances. As many as 217 of different substances of which 15 were identified as biocides, 17 as corrosion inhibitors or neutralizing agent, 17 were lubricity improvers and 38 different base fluids, lubricity solvents or surfactants, while 93 substances were not identified specifically and 37 substances occurred only once. This article is focused on the list of base fluids in straight oils and their possible health effects.

Study of Metalworking Fluids Biodegradability Potential Enhancement by the Prior Application of Ozone

The increases in biological mineralization of selected Metalworking fluids (MWF) pre-treated by ozone were investigated. There were studied 11 different fluids four of emulsion types, four of semi-synthetics and three of synthetic types. Expectations according to the literature review that the pre-treatment enhance the biodegradability of the metalworking fluids were not confirmed in 7 samples. Only 4 samples achieved after ozone pre-treatment better biological degradation. Enhanced biodegradability level after ozone pre-treatment step was observed in three emulsions (Samples 1, 2 and 3) and one semi-synthetics (Sample 7). While nontreated soluble oils reached biodegradability level from 45 to 73 %, after 1 hour of ozone treatment the biodegradability increased from 65 to 82 %. Semisynthetic metalworking fluid without any treatment reached 56 % of the biodegradability level. After one hour of ozone application increased the biodegradability level to 74 % and after 2 hours to 82 %. During ozone treatment it was observed the destabilization of emulsions in half of tested samples.

Influence of Cutting Environment on Tool Life

Abstract The issues of cutting environment and a suitable choice of cutting conditions by drilling are the main subjects of the article. Attention is paid to the application of the drilling process into the carbon steel. Analysed were the phenomena that adversely affect the tool life. The article demonstrated solutions how to remove these adverse effects. The multicriteria optimisation of input factors (cutting fluid concentration, cutting speed) for a defined target function (tool life) was applied. The measured values were subjected to mathematical–statistical analysis (ANOVA). Based on the implemented experiment and study of this issue, we determined the combinations of input factors, which achieved minimal values of target functions. Based on the implemented experiment and study of this issue, we also determined the combinations of input factors, which achieved minimal values of target functions. Based on this allegation, the most appropriate combination of the following input factors was proved: concentration 6.3 % and cutting speed 100 m/min.

Real Time Monitoring and Automatic Regulation System for Metalworking Fluids

Abstract A real-time monitoring and regulation system for metalworking fluids is being constructed to be installed in the Centre of excellence of 5-axis machining at the Faculty of Materials Science and Technology in Trnava. The article is focused on the description of the main components of the monitoring system and preliminary characterization of the software utilized in the regulation. The monitoring system will contain four probes to record real time values of pH, conductivity, temperature and concentration. After processing of recorded data by the LabVIEW software, an adjustment of the Metalworking fluid in the reservoir tank will be realized by the regulation part of the proposed system to optimum properties of the fluid, by adding water or concentrate. The designed device will provide an easy system which will control the quality of used metalworking fluid during its lifetime and maintain it on its optimum condition without human operator’s assistance.

The Study Into Potential Enhacement Of Metalworking Fluids Biodegradability By The Application Of O3/UV

Abstract The increase in mineralization and biodegradability of MWFs by ozone/ultraviolet in comparison with ozone were investigated. Studied were two similar synthetic fluids pre-treated by the combination of the O3/UV advanced oxidative method. Expectations that the pre-treatment could enhance biodegradability of the metalworking fluid were not confirmed. The combined oxidation process at the defined conditions resulted in 1-35 % decrease of the achieved primary degradation level. Samples were prepared from real concentrates and diluted to approximately 350 mg/L of TOC.

Well-Established Biodegradation Tests Used Biogenously Evolved Carbon Dioxide as an Analytical Parameter to Determine the Ultimate Biodegradability of Metalworking Fluids Measured by the Change of Absorption Solution Conductivity

Nowadays, there exist a few standardized tests in poor soluble substances ready biodegradability measurement. There are possibilities in evaluate the degradation by the O2 consumption or by CO2 releasing. Tests for O2 consumption are very stringent in keep the constant temperature because of the pressure which is the main parameter in O2 consumption calculating. On the other hand CO2 releasing test are complicated and discontinue because of the measuring by the titration methods. In present there is a possibility to measure CO2 produced by microbial activity during the substance degradation by the gaseous sensors. We were realized preliminary studies in continual measuring of evolved CO2 in biodegradability test of metalworking fluid Syntilo 81 BF by the conductivity measurement of absorption solution of barium hydroxide as it was described in [3,5].